Latch mechanism for doors and the like



March 1963 H. M. RIEGELMAN LATCH MECHANISM FOR moons AND THE LIKE 2 Sheets-Sheet 1 Filed Sept. 13, 19

flrraewens March 19, 1963 H. M. RIEGELMAN 3,

LATCH MECHANISM FOR DOORS AND THE LIKE Filed Sept. 13, 1961 2 Sheets-Sheet 2 INVENTOR. #4229 M 2/5651 MAW United States Patent 3,082,029 LATCH MECHANISM FOR DOORS AND THE LIKE Harry M. Riegelman, Rolling Hills, Calif., assignor to Security Aluminum Corporation, Compton, Calif., 21 corporation of California Filed Sept. 13, 1961, Ser. No. 137,791 20 Claims. (Cl. 292-49) This invention relates generally to latches, and more particularly, to a latch mechanism. for doors, windows, and the like.

Laterally sliding glass doors, for example, are normally provided with an inside latch or lock which can be operated to prevent the door from being opened from the outside. The latch mechanism usually includes a simple lever or handle which can be moved from one position to another to cause a latch structure to engage cooperative fixed jamb structure, and thus prevent movement of the door from a closed position.

Most of these latches or locks are simply constructed, and many cannot be easily adjusted after installation on the door. The actuating lever or handle on these latches can also be moved only partway to intermediate positions between latched and unlatched positions, and an unlatched or unlocked condition frequently results inadvertently.

That is, these latches do not have indexing means for ensuring that the latch is either in a fully latched or unlatched condition. Further, if the latch is placed in a latched condition while the door is open and the door is then closed, the latch structure is often and easily damaged by striking the fixed jamb structure.

It is an object of this invention to provide a new and useful latch mechanism which cannot be easily damaged and is especially suited for laterally sliding doors, windows, and the like.

Another object of the invention is to provide an easily adjustable latch mechanism for doors, windows, and the like.

Another object of the inventionis to provide an easily operated, positive snap action latch.

A further object of this invention is to provide a latch which can be easily engaged or disengaged by simple movement of a lever arm.

A still furthervobject of this invention is to provide a latch having jointly operated, multiple latching pawls.

Other objects, features and advantages of the invention will be apparent from the following description of a preferred embodiment of the invention, reference being made to the attached drawings, in which:

FIGURE 1 is a fragmentary, perspective view of one embodiment of my latch having a single latching pawl and constructed in accordance with this invention, installed on the stile of a sliding glass door;

FIGURE 2 is a plan view, taken along the line 2-2 as indicated in FIGURE 1, with an end plug deleted to show the construction within the latch housing;

. FIGURE 3 is an elevational view taken along the line 3-3 as indicated in FIGURE 2, to illustrate the latching and unlatching movement of the latch lever arm;

FIGURE 4 is a sectional view, taken along the line 4-4 as indicated in FIGURE 3, to illustrate the internal construction of the latching mechanism;

FIGURE 5 is a fragmentary, sectional view taken along the line 5-5 as indicated in FIGURE 4, to show keyways in a retainer block which can be engaged by a key afiixed to a latch pawl; Y

FIGURE 6 is an exploded view, illustrating the assembly arrangement of the latch mechanism;

FIGURE 7 is-a perspective view of the lever arm and retainer block showing the indexing structure thereon;

FIGURE 8 is a fragmentary elevational view illustrating the action of the indexing structure;

FIGURE 9 is a fragmentary, perspective view of a latch mechanism illustrating the use of multiple latching pawls in combination with the stile of a sliding glass door;

FIGURE 10 is a sectional view taken along the line 10-10 as indicated in FIGURE 9, to illustrate the structure of the actuating mechanism. for the latch shown in FIGURE 9;

FIGURE 11 is a fragmentary, bottom plan view of the latch mechanism shown in FIGURE 9, to illustrate the mechanism for simultaneously actuating the latching pawls; and

FIGURE 12 is an exploded view, showing the assembly arrangement of internal latch structure, the external housing structure being omitted for illustrative purposes.

Briefly, and in general terms, the latch mechanism according to this invention comprises a housing structure for rotatably mounting a retainer block. The retainer block has a spring-loaded, readily adjustable latching pawl suitably keyed thereto. As the retainer block is rotated on its axis, the latching pawl engages or disengages with a cooperating keeper or catch structure.

The housing structure preferably has a pair of spaced, parallel flanges, each flange having an opening therein, these openings being axially aligned. The retainer block has a main bore or central well therein, a reduced diameter bore through the bottom of the well, and at least one longitudinal keyway in the wall of the well. The latching pawl preferably is cylindrical, having an internally threaded, longiutdinal bore at one end thereof, a key near that end of the pawl, and a catch or retaining pin near the other end thereof. The pawl has a diameter which permits it to fit closely in the well such that the key engages the longitudinal keyway. A helically wound compression spring is longitudinally disposed in the well such that one end of the spring engages the shoulder or area around the reduced diameter bore, and the other end of the spring engages the end of the pawl which is passed through the opening in one of the flanges. The end of the pawl which is passed through the opening of one of the flanges has the internally threaded longitudinal bore which is threadably engaged by a screw having its head normally engaging the other of the flanges. The shaft of the screw extends through the opening of that flange, through the reduced diameter bore and the spring to thread into the threaded longitudinal bore of the pawl. Thus, the latching pawl is spring-loaded by the compression spring, and rotation of the retainer block on its axis rotates the latching pawl by means of the key which engages the longitudinal keyway in the well of the retainer block such that the catch pin on the end of the latching pawl is rotated to engage with or disengage from suitable catch structure.

The fragmentary perspective view of FIGURE 1 generally shows a latching mechanism according to this invention, whis is mounted to a laterally sliding glass door as an example of the utility of the latching mechanism. As can be seen in FIGURE 1, the latch mechanism 10 is mounted to stile 12 of a sliding glass door 14. The

-sliding glass door 14 moves laterally in the directions The end plugs 30 have been deleted in the top sectional view of FIGURE 2 to illustrate the internal arrangement of the latching mechanism 10. The housing structure 20 is secured to stile 12 by screws 28, which respectively engage tubular, internally threaded screws 32, as indicated in FIGURE 2. The internal screws 32, in a manner similar to the external screws 28, fasten a pull handle 34 to the stile 12. The external screws 28 and internal screws 32 pass through respective walls of the stile 12, and are threadably engaged within the stile. The housing structure 20, and the pull handle 34 are secured in position by suitably tightening the external screws 28.

The sliding glass door 14 is shown in a closed and latched condition in FIGURE 2. In the closed position, the outer end of the stile 12 fits into a vertical channel 36 of the jamb structure 18. At the same time, the latching pawl 38 is positioned in an adjacent vertical channel 40. With the lever arm 26 in the position shown in FIGURE 2, a catch pin 42 near the end of the pawl 38 is moved into a vertical side channel 44 to engage the catch structure 46. The sliding glass door 14 is then in a latched condition, which prevents opening thereof without first moving the lever arm 26 upwards to the open position. When the lever arm 26 is moved upwards, the pawl 38 is rotated such that the catch pin 42 is moved out of the channel 44 and away from engagement with the catch structure 46, thus freeing the sliding glass door 14 for lateral opening movement.

The internal construction of the latch mechanism is shown more clearly in the sectional view of FIGURE 4. The housing structure 20 includes two spaced flanges 48 and 56, which have respective openings 52 and 54 that are in axial alignment. The opening 52 permits passage of one end of the pawl 38, and also slidably supports the shank of the pawl. The opening 54 similarly permits passage of the shank of a screw 56, and also supports the same. The opening 52 is a circular opening having diametrically opposite notches 52a and 52b. These notches can be seen in FIGURE 3 (see also FIGURE 6). As was mentioned before, the opening 52 permits passage of an end of the pawl 38. The notches 52a and 52b are provided to permit passage of a key 58, which is located on the pawl 38 near one end thereof. The key 58 is in the form of a small pin orthogonally disposed to the surface of pawl 38, similar to the catch pin 42. The notches 52a and 52b are provided in the opening 52 to permit passage of the key 58 through one or the other notch in order to establish a latched condition for the lever arm 26 in either.

date the key 58, as shown in FIGURE 5. The well 62 accommodates a helically wound spring 64, as shown in FIGURE 4, and one end of the spring 64 engages with the annular area around the internally threaded end of the pawl 38. The diameter of the well 62 is such that it slidably accommodates the shank of pawl 38. A reduced diameter bore 66 is provided through the bottom or end of the well, as shown in FIGURE 4, to permit passage of the screw 56 which threadably engages the internally threaded end of the pawl 38. One end of the helical spring 64 engages the shoulder or area around the reduced diameter bore 66, and the other end, of course, engages the end of the pawl extending into the well 62. The pawl 38 is thus spring-loaded by the helical spring 64, which is generally compressed by the screw 56 threadably engaging the pawl 38.

The longitudinal keyways 62a and 62b, shown in FIG- URE 5, can be selectively engaged by the key 58 according to whether it is desired to have a latched condition for the lever arm 26 in either the down or raised position. The keyway 62a will be aligned with the notch 52a when the lever arm 26 is placed in the raised position, Whereas the keyway 62b will be aligned with the notch 52b when the lever arm is placed in the down position.

The key 58 is diametrically opposite the catch pin 42, as seen in a plan view. Thus, when the key 58 is passed through the notch 52a, the lever arm 26 must be in a raised position before the key 58 will enter the keyway 62a. Since the catch pin 42 is then diametrically opposite the notch 52a, as seen in FIGURE 3, this establishes an unlatched condition for the lever arm 26 in the raised position. Similarly, if the key 58 is passed through the notch 52b, the lever arm 26 must be in a down position in order that the key 58 can enter the keyway 62b. The catch pin 42 will then be diametrically opposite the notch 52b to establish an unlatched condition for the lever arm 26 in the down position. The length of the keyways 62a and 62b extends from one end of the well 62 to a distance near the reduced diameter bore 66 such that the keyways can slidably engage the key 58 for spring plunger travel of the pawl 38 to a maximum point where the catch pin 42 contacts the flange 48.

The lever arm 26 has a snap action movement which is produced by a detent mechanism. The detent mechanism can take the form of a leaf spring 68, the ends of which are braced against the flange 50, as shown in FIGURE 4. The leaf spring 68 is bowed such that only the ends thereof contact the flange 50. A hole 70 is provided at the center of the leaf spring 68 to allow passage of the shank of the screw 56. The leaf spring 68 is bent to produce two apexes which are diagonally opposite the hole 70, as illustrated in FIGURE 6. The apexes 72a and 72b are triangularly shaped such that the peak ridges thereof are aligned at right angles to the parallel sides of the leaf spring 68.

The detent mechanism or the apexes of the shaped leaf spring 68 cooperatively engages two triangularly shaped indexing teeth 74a and 74b, which are shown in FIG- URE 7. As can be seen in FIGURE 7, the teeth 74a and 74b are diametrically opposite, and positioned about the bore 66. In operation, the tooth 74a will be positioned on one side or the other of the apex 72a, and the tooth 74b will be positioned on one side or the other of the apex 721:. This is diagrammatically shown in FIG- URE 8, and since the indexing teeth 74a and 74b are diametrically opposite the bore 66, it can be easily seen that the leaf spring 68 is slightly compressed as the teeth 74a and 74b pass respectively over the apexes 72a and 72b, respectively. Accordingly, a snap action is provided to the lever arm 26.

Assembly of the latch mechanism shown in FIGURES 1 through 8 is commenced by first placing the helical spring 64 into the well 62, and passing the lever arm 26 thorugh the rectangular opening 24 of the housing structure 20. The leaf spring 68 is then slipped between the flange 5t and the end of the retainer block having the teeth 74a and 7412 such that the hole is aligned with the reduced diameter bore 66. The lever arm 26 is placed in either the down or raised position as desired for an unlatched condition. Next, the internally threaded end of the pawl 38 is passed through the opening 52 with the key 58 passed through either notch 52a or 52b, according to which notch is aligned with one of the keyways 62a or 62b. The screw 56 is then passed through the holes 54 and 70, the reduced diameter bore 66, and the helical spring 64 to threadably engage the internally threaded end of the pawl 38. The screw 56 is threaded into the end of pawl 38 until the catch pin 42 is located at approximately the desired distance to engage the catch structure 46.

One of the plugs 30 is then positioned between the flanges 48 and 50 such that one of the screws 28 can be passed through a hole in the housing structure 20 and through an aligned hole in the plug 30. The pull handle 34 is then properly positioned on the stile 12, and one of the internal screws 32 is passed through the corresponding hole in the pull handle 34 and in the wall of the stile 12. The screw 28, with its corresponding plug 30 in place, is then passed through the other wall of the stile 12 and turned by a screwdriver to thread into the corresponding internal screw 32. In like manner, the other screw 28 and plug 30 are assembled and the screw 28 is threaded into the other internal screw 32. The screws 28 are firmly tightened to hold the housing structure 20 and handle 22, and the pull handle 34 solidly in position.

The sliding glass door \14, with the latch mechanism installed, is then moved to a closed condition. The lever arm 26 is then snapped to a latched position, and the door 14 is then tested to determine if the catch pin 42 is properly positioned with respect to the catch structure 46. Adjustmlent of the position or the catch pin 42 is easily madewith a screwdriver adjusting the screw 56. Latching action which prevents opening of the sliding glass door 14 is obtained through the catch structure 46 engaging the catch pin 42 which, through the threaded engagement with screw 56, in turn holds the head of screw 56 against the flange 50 to prevent the housing 20, attached to stile .12, (frommoving away itrom the jambstructure 18.

It is noted that if the door 14 was in an open position and if the lever arm 26 was inadvertently placed in a latched position, the catch pin 42 would strike the catch structure 46-, if the door was then moved toward a closed position. However, the spring plunger action of pawl 38 allows compression of the helical spring 64 as the catch pin strikes the catch structure 46 to prevent any strain on the latch mechanism which would materially shorten its life. As the helical spring 64 is compressed by the end of the pawl 38, the head of the screw 56 moves away from the flange 50 while the helical spring 64 provides its cushioning effect. This completes the description of one embodiment of the invention.

A latch mechanism following this invention and having multiple latching pawls is generally shown in FIG- URE 9. The latch mechanism 80 is mounted on the stile 82 of the sliding glass door 84 in a manner similar to the mounting of the latch mechanism 10 on the stile 12 of the sliding glass door 14. The stile 82 engages jamb structure 86 which is similar to the jamb structure 18 shown in FIGURE 1. The vertical channel 88 corresponds to the channel 40, and the side vertical channel 90 cor-responds to the side channel 44, and the catch structure 92 corresponds .to the catch structure 46 shown in FIGURE 2. The catch structure 92, is, of course, engaged by the catch pins of the multiple pawls of the latch mechanism 80. i

The latch mechanism 80 includes a housing structure 94 and a handle 96 which is affixed thereto. The housing structure 94 and the handle 96 correspond respecthe housing structure 94, as shown in FIGURE 9, and is used to operate the latch mechanism 80. Rotary movement of the thumb lever 98 on its pivot axis causes latching and unlatching of thelatch mechanism 80. Thus, the thumb lever 98 corresponds to the lever arm 24 of the latch mechanism shown in FIGURE 1.

The thumb lever 98 is afiixed to one end of a cam} shaft 100 by means of a screw 102, as shown in the crosssectional view of FIGURE 10. Afiixed radially to the shaft 100, perpendicular to the axis thereof, is asectorshaped cam 104 having an arcuate slot 106 therein which engages a boss or stud 108 projecting from the housing structure 94.

' The end of the shaft 100 which extends outside of the housing structure 94 is milled to a square tform which can be capped by the thumb lever 98 in different angular positions. For example, the thumb lever 98, as shown in FIGURE 9, is in a position corresponding to an unlatched condition and by moving the thumb lever 98 downward to a generally vertical orientation, the latch mechanism 80 is placed in a latched condition. If it is desired that the position of the thumb lever 98, as shown in FIGURE 9, represent a latched condition, then the squared end of the shaft simply provides slip-free engagement with a square hole 110 in the thumb lever 98. A tension washer i112 is located between the collar 114 and the surface of the housing structure 94 to prevent play in an axial direction.

The sides of the cam 104 are contoured to engage and operate a rack 116. The shaft 100 passes through a slot 118 and is journaled in a hole 120 in the stile 82. The tension washer 112 maintains the rack 116 against two narrow ridges 122 and 124, against which the rack moves. The rack mechanism is shown more clearly in FIGURE 11, which is an internal elevational view of the latch mechanism within the housing structure 94. The rack 1'16 is positioned within the housing. structure 94 between generally vertical flanges 126 and 128. These flanges, of course, correspond generally to the flanges 48 and 50 shown in FIGURE 4. The rack 116 includes two gear sections 130 and 132 which are separated by a central, oii set or raised section 134. This arrangement is more clearly shown in the exploded View of FIGURE 12.

The teeth of the rack section 130 mesh with the teeth on a gear sector retainer block 136 and the teeth on the other rack section 132 mesh with the teeth of a gear sector retainer block 138, as shown in FIGURE 11. The gear sector 136 has a collar on one end thereof which is grooved or notched along two right-angular diameters, as illustrated in the exploded view of FIGURE 12. Similarly, the gear sector 138 has a collar 152 which is similarly grooved or notched along two right-angularly oriented diameters. The indexing grooves or notches on the collars 140 and 142 respectively engage apex pairs 144 and 146 which are provided in the flange 128 of the housing structure 94, as indicated in FIGURE 11. The apex pairs 144 and 146 are similar to the apexes 72a and 7212 on the leaf spring 68, shown in FIGURE 6. Thus, the apex pairs 144 and 146 in the flange 128 are respectively provided as detents for engaging the indexing grooves or notches on the collars 140 and 142 of the gear sectors 136 and 138.

The apex pairs 144 and 146 have holes between apexes which correspond to the hole 70 in the leaf spring 68, to permit passage of screws 148 and 150 which are similar to the screw 56 shown in FIGURE 4. The gear sectors 136 and 138 each correspond to the retainer block 60, and are similar to the remaining structure thereof. The pawls 152 and 154 are each similar to the pawl 38, and the springs 156 and 158 are each similar to the helical spring 64 of the latch mechanism 10. Thus, it will be apparent that the two latch structures of FIG- URE 12 are each similar to thelatch structure shown in FIGURE 4, and are jointly operated by a raclr and cam mechanism to cause the catch pins 160 and 162 to engage or disengage the catch structure 92 in order to' latch or unlatch the sliding glass door 84.

The stud 108, shown in FIGURE 10, serves as a guide pin for the cam 104 as it is rotated by the thumb lever 98. The end of the shaft 100 passing through the, slot 118 similarly serves to guide the rack 116 as it is moved up and down by action of the contoured sides of the cam 104 acting against the inner walls of the central section 134. In FIGURE 11, as the cam 104 is rotated in a clockwise direction with rotation of the thumb lever 98,

' the side 104a of the cam presses against the wall 134a to move the rack in a downward direction. In so doing, the gear sectors 136 and 138 are rotated to bring the catch pins 160- and 162 into latching engagement with the catch structure 92. Reversing the movement of the thumb lever 98 back to its original position would,

of course, return the rack 116 to its former position to unlatch the latch mechanism 86.

.gear sectors 136 and 138 have gear teeth which are not as long as the gear teeth in rack sections 136 and 132. Thus, as the gear sectors 136 and 138 are rotated by the rack 116, the detent apex pairs 144 and 146, operating with the grooves or notches in the collars 140 and 142, cause the gear sectors to move laterally as the apex pairs are moved from one set of notches to the set at right angles thereto. Thus, the helical springs 156 and 158 act to hold the grooves or notches in the collars 146 and 142 against the apex pairs 144 and 146. This, of course, produces a snap action similar to that provided in the latch mechanism 10, as the gear sectors 136 and 133 are rotated by the rack 116. In this way, a leaf spring such as 68, used in the latch mechanism 10, is not necessary to produce a snap action movement.

Two versions of the latch mechanism according to this invention have been shown and described with respect to sliding glass doors. The invention is, of course, useful for other types of closure members besides sliding doors. The latch mechanism, for example, can also be used with swinging doors, as contrasted from sliding doors. In this instance, suitable catch structure would be engaged when the catch pin 42 (or catch pins 160 and 162) is moved to a down or vertical direction after entering a horizontally disposed channel in the jamb structure. Other versions and modifications of the invention can be readily made. Accordingly, it is to be understood that the particular embodiments of the invention described above, and shown in the drawings, are merely illustrative of and not restrictive on the broad invention, and that various changes in design, structure and arrangement made be made without departing from the spirit and scope of the appended claims.

I claim:

1. Latch mechanism, comprising: a retainer block including a bore on a longitudinal axis; a latching pawl having a catch near one end thereof, said pawl slidably fitting into said bore; fastening means extending into sa1d bore to engage said pawl; means defining a shoulder within said bore; compression spring means disposed within said bore, one end of said spring means abutting said shoulder and the other end abutting said pawl; means for rotatably mounting said retainer block; means for maintaining said pawl in a fixed angular orientation relative to said retainer block; and means for rotating said retainer block on said longitudinal axis whereby said catch engages and disengages cooperative catch structure.

2. Latch mechanism, comprising:v a retainer block including a bore on a longitudinal axis and having a main bore portion and a reduced diameter bore portion;

a latching pawl having a catch near one end thereof, said pawl slidably fitting into said main bore portion; fastening means extending through said reduced diameter bore portion into said main bore portion to engage said pawl; means for rotatably mounting said retainer block; means for maintaining said pawl in a fixed angular orientation relative to said retainer block; and means for rotating said retainer block on said longitudinal axis whereby said catch engages and disengages cooperative catch structure.

3. Latch mechanism, comprising: a retainer block including a bore on a longitudinal axis and having a main bore portion and a reduced diameter bore portion, and a longitudinal keyway in the wall of said main bore portion; a latching pawl having a key near one end and a catch near the other end thereof, said pawl slidably fitting into said main bore portion and said key slidably engaging said longitudinal keyway; fastening means extending through said reduced diameter bore portion into said main bore portion to engage said pawl; means for rotatably mounting said retainer block; and means for rotating said retainer block on said longitudinal axis whereby said catch engages and disengages cooperative catch structure.

4. Latch mechanism, comprising: a retainer block including a bore on a longitudinal axis and having a main bore portion joining with a reduced diameter bore portion to produce a junction shoulder, and a longitudinal keyway in the wall of said main bore portion; a latching pawl having a key near one end and a catch near the other end thereof, said pawl slidably fitting into said main bore portion and said 'key slidably engaging said longitudinal keyway; fastening means extending through said reduced diameter bore portion into said main bore portion to engage said pawl; a compression spring disposed in said main bore portion, one end of said spring engaging said shoulder and the other end engaging the end of said pawl slidably fitting into said main bore portion; means for rotatably mounting said retainer block; and means for rotating said retainer block on said longitudinal axis whereby said catch can engage and disengage cooperative structure.

5. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; a retainer block having a Well therein, a reduced diameter bore through the bot-tom of said well, and a longitudinal key way in the wall of said well; a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a compression spring disposed in said well between said pawl and said reduced diameter bore; a fastening means having an end normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

6. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having an internally threaded longitudinal bore, key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; :a compression spring disposed in said wall between said pawl and said reduced diameter bore; a screw having a head normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

7. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having an internally threaded longitudinal bore, a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a compression spring disposed in said well between said pawl and said reduced diameter bore; a screw having a head normally engaging the other of said flanges and a shaftextending through said opening of said other of said flanges, said reduced diameter bore and said spring to thread intosaid threaded longitudinal bore of said pawl; and means for rotating said a 10. Latch retainer block on a central axis axially .aligned'with said openings, including a lever arm aflixed to said retainer b'oc 8. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having an internally threaded longitudinal bore, a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyw-ay; a compression spring disposed in said well between said pawl and said reduced diameter bore; a screw having a head normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings, including gearing aflixed to said retainer block, a rack adapted to mesh with said gearing, and means for reciprocating said rack whereby said retainer block can be rotated on said axis.

9. Latch mechanism; comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said openingin one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area around said reduced diameter bore and the other end thereof engaging area around the end of said pawl extending through said opening of said one of said flanges; a fastening means having one end normally engaging theother of'said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned,

respective openings therein; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well,,and a longitudinal keyway in the ,wall of said well; a latching pawl having an internally threaded longitudinal bore, a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, sad key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area around said reduced diameter bore and the other end thereof engaging area around said threaded longitudinal bore of the end of said pawl extending through said opening of said one of said flanges; a screw having a head normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, 'said reduced diameter bore and said spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

11. Latch mechanism, comprising: housing structure inoluding a pair of spaced flanges having axially aligned,

respective openings therein, and detent structure positioned thereon; a retainer block having a central well therein, a reduced diameter bore through the bottom" of said well, a longitudinal keyway in the wall of said well, and indexing structure for engaging said detent structure;

a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal lreyway; a compression spring disposed in said well between said pawl and said reduced diameter bore; a fastening means having an end normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

12. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein, and detent structure positioned thereon; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, a longitudinal keyway in the wall of said well, and indexing structure for engaging said detent structure; a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area around said reduced diameter bore and the other end thereof engaging area around the end of said pawl extending through said opening in one of said flanges; a fastening means having an end normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

13. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein, and detent structure positioned thereon; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, a longitudinal keyway in the wall of said well, and indexing structure for engaging said detent structure; a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring on gaging area around said reduced diameter bore and the other end thereof engaging area around the end of said pawl extending through said opening of said one of said flanges; a fastening means having an end normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings, including gearing affixed to said retainer block, a rack adapted to mesh with said gearing, and means for recipro- V eating said rack whereby said retainer blockcan be rotated on said axis.

14. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned,

respective openings therein, a leaf spring positioned on one ofsaid flanges and having detent structure thereon; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, a longitudinal keyway in the wall of said well, and indexing structure for engaging said detent structure; a latching spring disposed in said well between said pawl and said reduced diameter bore; a screw having ahead normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said compression spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

15. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein, and detent apex structure positioned about one of said openings; a retainer block having a central well therein, a reduced diameter bore through the bottom of said well, a longitudinal keyway in the wall of said well, and notched indexing structure for engaging said detent apex structure; a latching pawl having an internally threaded longitudinal bore, a key near one end and a catch pin near the other end thereof,

said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area around said reduced diameter bore and the other end thereof engaging area around said threaded longitudinal bore of the end of said pawl extending through said opening of said one of said flanges; a screw having a head normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings.

16. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; at least one retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a compression spring disposed in said well between said pawl and said reduced diameter bore; a fastening means having an end normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings, including gearing aflixed to said retainer block, a rack mounted between said flanges and adapted to mesh with said gearing, a cam adapted to engage said rack for reciprocating the same, and means for actuating said earn whereby said retainer block can be rotated on said axis.

17. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; at least one retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having an internally threaded longitudinal bore, a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a compression spring disposed in said well between said pawl and said reduced diameter bore; a screw having a head normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings, including gearing aflixed to said retainer block, a rack mounted between said flanges and adapted to mesh with said gearing, a cam adapted to engage said rack for reciprocating the same, and means for actuating said cam 12 whereby said retainer block can be rotated on said axis.

18. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; at least one retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having an internally threaded longitudinal bore, a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area around said reduced diameter bore and the other end thereof engaging area around said threaded longitudinal bore of the end of said pawl extending through said opening of said one of said flanges; a fastening means having an end normally engaging the other of said flanges and a shaft extending through said Opening of said other of said flanges, said reduced diameter bore and said spring to engage the end of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings, including gearing affixed to said retainer block, a rack mounted between said flanges and adapted to mesh with said gearing, a cam adapted to engage said rack for reciprocating the same, and means for actuating said cam whereby said retainer block can be rotated on said axis.

19. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein; at least one retainer block having a central well therein, a reduced diameter bore through the bottom of said well, and a longitudinal keyway in the wall of said well; a latching pawl having an internally threaded longitudinal bore, a key near one end 0 and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area. around said reduced diameter bore and the other end thereof engaging area around said threaded longitudinal bore of the end of said pawl extending through said opening of said one of said flanges; a screw having a head normally engaging the other of said flanges and a shaft extending through said opening of said other of said flanges, said reduced diameter bore and said spring to thread into said threaded longitudinal bore of said pawl; and means for rotating said retainer block on a central axis axially aligned with said openings, including gearing aflixed to said retainer block, a rack mounted between said flanges and adapted to mesh with said gearing, a cam adapted to engage said rack for reciprocating the same, and means for actuating said cam whereby said retainer block can be rotated on said axis.

, 20. Latch mechanism, comprising: housing structure including a pair of spaced flanges having axially aligned, respective openings therein, and detent apex structure positioned about one of said openings; at least one retainer block having a central well therein, a reduced diameter bore through the bottom of said well, a longitudinal keyway in the wall of said well, and notched indexing structure for engaging said detent apex structure; a latching pawl having a key near one end and a catch pin near the other end thereof, said pawl extending through said opening in one of said flanges and slidably fitting into said well, said key slidably engaging said longitudinal keyway; a helically wound compression spring longitudinally disposed in said well, one end of said spring engaging area around said reduced diameter bore and the other end thereof engaging area around the end of said pawl extend- 13 14 opening of said other of said flanges, said reduced diamand means for actuating said cam whereby said retainer eter bore and said spring to engage the end of said pawl; block can be rotated 011 said 8 and means for rotating said retainer block on a central References Cited in tm file of this patent axis axially aligned with said openings, including gearing affixed to said retainer block, a rack mounted between 5 UNITED STATES PATENTS said flanges and adapted to mesh with said gearing, a cam 363,595 Kmg 1887 v v a 1,150,450 Phillips Aug. 17, 1915 adapted to engage sa1d rack forreciprocatin the same, 1,496,172 Rogers June 3, 1924 

1. LATCH MECHANISM, COMPRISING: A RETAINER BLOCK INCLUDING A BORE ON A LONGITUDINAL AXIS; A LATCHING PAWL HAVING A CATCH NEAR ONE END THEREOF, SAID PAWL SLIDABLY FITTING INTO SAID BORE; FASTENING MEANS EXTENDING INTO SAID BORE TO ENGAGE SAID PAWL; MEANS DEFINING A SHOULDER WITHIN SAID BORE; COMPRESSION SPRING MEANS DISPOSED WITHIN SAID BORE, ONE END OF SAID SPRING MEANS ABUTTING SAID SHOULDER AND THE OTHER END ABUTTING SAID PAWL; MEANS FOR ROTATABLY MOUNTING SAID RETAINER BLOCK; MEANS FOR MAINTAINING SAID PAWL IN A FIXED ANGULAR ORIENTATION RELATIVE TO SAID RETAINER BLOCK; AND MEANS FOR ROTATING SAID RETAINER BLOCK ON SAID LONGITUDINAL AXIS WHEREBY SAID CATCH ENGAGES AND DISENGAGES COOPERATIVE CATCH STRUCTURE. 